low oil when hot hot idle?

When oil gets hot it tends to thin out. Of course you don't want the pressure to get to low, like less than 10 lb or something. Someone else can give a better number. But if it gets too low, your pump might be getting worn out. Oh, do you have a gauge or the light in the dash? If light, a mechanical gauge would give you a better idea of what your pressure really is. The light is a crap shoot.